We have used the patch clamp technique to identify further intermediate molecular steps linking receptor activation by inhibitory neuropeptides to protein phosphatase stimulation, to identify a second, novel phosphorylation site on calcium- and voltage-dependent potassium channels with distinct regulation and consequences for channel function, and to identify other peptides and channels that initiate or are regulated by this pathway. In addition, we have cloned and are expressing the potassium channels and proteinphosphatases to confirm our hypotheses at the molecular level.